i currently have 1.3mm skimmed off my head which i think gives me around 10.3:1 compression ratio. Torque down low has very noticably increased.
I was wondering what compression you all think the standard bottom end will take. I know i cant skim more than about 1.6mm or else it will start cuting into the bowl area.
just curious as i was thinking about building another head.
I would worry about your piston to valve clearance ,and the fact that your valve seats are closer to the head.Besides that i think stock pistons can handle a lot of compression.You see a lot of guys running 12 :1 compression on p29 pistons and such.It just all depends on what condition your piston rings and pistons are.
If you want more compression then 10,3 :1 you would be better of getting high compression pistons.Milling your head to 1.6mm gives you 10,7 :1 compression which isn't really worth the trouble.
Btw the bowl area is inside the intake/exhaust ports.And the D14a4 's quench area is about 2.5mm deep .
Quote from Endyn:"The combustion chamber is a better shape than the DOHC.So don't chunk those 1.6 SOHC engines, they can make really good power. For a pure performance application, regardless of application, I'd choose the SOHC. No bull!"
yea thats y i can only skim around 1.6mm off the head because of the piston to valve clearance. dont think i could go anymore or else i wuld start to run into trouble.
high compression pistons could be an idea altho i dnt fancy spending too much money on them.
Can i ask you guys, what is a good value for skim a D16Y8 head with stock pistons? remember, D16Y8 head is lot more "closed", with smaller chambers. cheers
Law_ wrote:Can i ask you guys, what is a good value for skim a D16Y8 head with stock pistons? remember, D16Y8 head is lot more "closed", with smaller chambers. cheers
D16y8 head has the quench pads closed up which gives you a bigger quench area which is better in high compression ratio like 12 :1.Less prone to pre detonation.
If you mill the head 0.025" or 0.64mm you'll get a compression ratio of 10:1 on a D14a4/a3 bottem end. 0.025" milled is not too much imo.
Quote from Endyn:"The combustion chamber is a better shape than the DOHC.So don't chunk those 1.6 SOHC engines, they can make really good power. For a pure performance application, regardless of application, I'd choose the SOHC. No bull!"
